Method and apparatus for manufacturing metallic strip



June 13, 1939. Q H MANlQN` 2,162,407

METHOD AND APPARATUS FOR MANUFACTURING METALLIC STRIP E@ ATTORNEYl- Junei3, 1939. c. H. MANION. 291527407 METHOD AND APPARATUS FOR MANUFACTURINGMETALLIC STRIP Filed Sept. 1l,v 1937 3 Sheets-Sheet '2 AIEEII N om mJune 13, 1939. C. H. MANlON 2,162,407

METHOD AND APPARATUS FOR MANUFACTURING METALLIC STRIP Filed Sept. ll,1937` 3 Sheets-Sheet C5 Qu ATTORNEY@ Patented June 13, 1939 PATENTOFFICE IVIETHOD AND APPARATUS FOR MANU- FACTURING METALLIC STRIP CharlesH. Manion, Follansbee, W. Va., assignor to United Engineering andFoundry Company, Y Pittsburgh, Pa., a corporation of Pennsylvania.

Application September 11, 1937, Serial No. 163,359

17 Claims.

` This invention relates to a method and apparatus for reducing hotingots to cold rolled strip steel, and more particularly to a, millarrangement or layout for this purpose and to a method of rollingpracticed in connection therewith.

The customary practice in producing cold rolled metal strip from hotingots is to roll the hot ingots into slabs in a blooming or slabbingmill, shear'the slabs, and transfer them to a reheating furnace.Thereafter the slabs are further reduced in a hot roughing mill whichmay comprise several separate sets of roll stands. Next the ends of theresultant strip are cropped and the strip then hot rolled in a hot stripmill which i5 also comprises several separate sets o roll stands. Afterthe strip leaves the hot mill, it may be pickled and then cold rolled ina cold rolling mill which, like the hot mill, may comprise severalseparate sets of roll stands. Large tonnage can ,0 be produced with sucha method and apparatus, but it Will be appreciated that very greatinitial and operating costs are involved because so many different typesof mills and drives and auxiliaries are required, so much space isrequired for the 5 equipment, and such a relatively-large number of menare required to control the operations ci the various machines.

Due to these exceedingly high initial and operating costs and the largeinvestment necessi- 0 tated thereby, small companies that do not requirea large tonnage ci strip steel are discouraged or prevented fromrollingstrip cold, or iin-d it necessary to have other companies do part o theWork, such as produce the slabs or even the hot strip. In some cases itis possible to get along with less equipment by arranging it so thatsome of it serves a dual purpose, but this saving is largely lost by theincreased cost of production resulting from the fact that while part ofthe 40- equipment is serving its dual purpose other parts must standidle while waiting for the material being processed. Money invested inexpensive mill equipment which is not used at all during a large part ofthe strip-forming operation adds d greatly to production costs.

It is among the objects of this invention tc provide for reducing ingotsto cold rolled strip by apparatus the initial cost of which ismaterially reduced relative to the cost of apparatus used for thispurpose heretofore, by apparatus substantially all of which ismaintained in continuous operation while rolling is progressing so as tohold production costs down to a reasonable level, and by apparatus forwhich a minimum of operators 'f5 and oor space is required, Anotherobject is (C1. Bil- 311) to provide a method of hot and cold rolling bywhich iulllment of the above-mentioned objects is made possible.

In accordance with this invention hot ingots are reduced to slabs inthesame mill that is later used as a roughing stand for reducing theslabs to rough strips or bars after the former have been sheared andreheated. It is preferred to use a, reversing universal mill for thispurpose, and to remove the slabs from its run-out table after they havebeen sheared so as to deliver them to a slab yard through which they aresubsequently charged into a reheating furnace located beside the millsentry table. As fast as bars are rolled in the universal mill they arecropped by the slab shear and conveyed by the run-out table directly toa hot strip mill, preferably of the continuous type, in which they arefurther reduced to strips which are coiled for storage to be followed atthe proper timeby pickling, if desired., The strip mill is adapted tohave its rolls for hot strip rolling removed and replaced by rollssuitable for cold rolling (hereinafter referred to as hot and coldrolls, respectively), and similarly its strip guiding equipment ischangeable to guiding equipment suitable for cold strip rolling. Thesame mill is also operatively connected with an uncoiler and one or morestrip reels. The uncoller and the strip reels may be arranged in anymanner which is suitable to secure cooperation with the strip mill, butI prefer, for the sake of simpiiclty, that arrangement in which they arelocated below displaceabie sections 'of the conveyor tables at the entryand delivery ends of the strip Tnil.

After all of the slabs that were produced by the universal mill havebeen rolled into bars and the bars have been roled into hot strip, coldvrolls are substituted for the hot rolls of the strip `mill, the stripguiding equipment between the and the removable table sections areremoved to uncover the uncoller and reel. The coils of hot rolled strip,which have cooled with self-annealing if desired, and which may havebeen pickled in the meantime, are then placed in the uncoller and thestrip is cold'rolled in the strip mill and removed as coils from thereel.

While the cold rolling is proceeding in the strip mill, the universalstill continues in uninterrupted operation rolling another supply ofingots into additional slabs that are fed into the reheating furnace,and as soon as the cold rolling is iinished and the hot rollingequipment' and table sections are replaced, these slabs, like the:-

stands is changed to that suitable for cold strip, j

the reversible universal mi ll until reduced to a preceding supply, arereduced inthe universal mill to bars which are carried by the run-outtable directly to the strip mill where they are hot rolled into strip.Thiscycle of operation is repeated over and over again-as long as ingotsare available, and it will therefore be apparent that both `mills aswell as the rest of the equipment operate substantially all of the timewith no prolonged and costly periods during which part of the apparatusmust vnecessarily stand idle. By rolling metal with this apparatus andaccording to this method, sulcient tonnage of cold` showing the rest ofthe apparatus; Fig. 3 is an enlarged side view of the uncoiler andassociated parts taken on the line III-III of Fig. 2; and Fig. 4 is aside view, similar to Fig. 3, of the cold strip reel taken on the lineIV-IV of Fig. 2, Referring to Fig. 1 of the drawings, an ingot buggy Ior other suitable device is adapted to deliver hot ingots to one end ofa driven entr-y table 2 at the opposite end of which there is a mill 3in which the ingots are reduced to slabs. As it is an object of thisinvention to provide as little rolling equipment as possible, a singlereversing universal mill is used because its vertical rolls make itunnecessary to provide for ingot-turning apparatus. lAt the deliveryside of the mill there is a driven run-out table I on which the slabsare conveyed through a shear 6' by which they are cut into suitablelengths with the help of a shear gauge l.. As the slabs leave the shearthey are pushed laterally off the runout table and onto transferapparaltus 8 by means of a reciprocable slab pusher 9 mounted on theopposite side of the table. 'I'he transfer apparatus is of any suitableform, such as an endless chain conveyor disposed substantially at rightangles to the table, and transports the slabs from the table to a pilerI I.

`As soon as a sizable pile of slabs has been formed in this manner, theslabs are transferred. to the slab yard where they are inspected.processed and stored; and from storage they are delivered by anysuitable means, such as crane hook I2, to an unpiler disposed at one.end of a reheating furnace I3, the opposite end of which is positionedadjacent one side of entry table 2. The unpiler preferably comprises anelevatable support I4 for the pile of slabs, and reciprocable arms I6for pushing the top slab from the pile into the furnace. Each time thearms are retracted the support is elevated to bring the top slab intothe path of the arms. As the slabs are pushed through the reheatingfurnace in this manner the foremost one is pushed out onto entry table 2where its lateral movement is arrested by stops I'I mounted on theopposite side of the table. Delivery of ingots from the. soaking pit tomill 3 is then discontinued and the rolling of slabs delivered from thefurnace I3 then takes place.

In accordance with this invention, each successive hot slab is rolledback and forth through size suitable for rolling ito strip. Stock thathas been thus reduced is referred to herein as bars. 'I'he bars arecarried by run-out table 4 'through shear 6, where their ends arecropped, and past slab transfer apparatus 8 to a strip mill I3, of whichfour stands are shown in Fig. 2 of the drawings. Each bar is reduced inthe strip mill, which is preferably a continuous mill, to

hot strip steel that moves over agdelivery table I3 to a hot coiler 2|.Preferably, two vcoilers are provided, each in line with the mill withthe usual gate 22 in front of the first one for guiding the hot stripinto either one of the coilers. Each coil thus formed is removed fromits coiler by any suitable means, such as the coil unloader 23 shown inPatent`No. 2,092,539, and deposited on a conveyor 24 by which it isconveyed to a storage area from which it may later be taken to bepickled. When in storage the coils cool off slowly because of theclosely wrapped convolutions of the strip and the result is aself-,annealing of the strip which is often advantageous.

It will thus be seen that with a minimum of 'apparatus ingots arereduced to hot strips which are coiled and stored; the universal mill,shear, andentry and run-out tables being used for the dual purpose offorming slabs from ingots andV bars from the slabs. It follows that aminimum of floor space and a reduced number of operators are requiredfor this apparatus.

In keeping with the foregoing, it is a feature of this invention thatthe strip mill i8 is convertible into a hot or cold mill wherebysubstantially one strip mill and its operators are eliminated, and fulluse is made of strip mill I8 and its operators. That is, strip is coldrolled in this mill after all of the bars have been reduced, wherebyshutting down of the strip mill while more slabs are being made isavoided. Accordingly, the strip mill is adapted to receive either hotor-cold rolls, i. e., rolls suitable for hot rolling and rolls designedfor cold rolling, to receive strip-guiding equipment for either type ofrolling, and the mill drives are suitable for both hot and cold rolling.Roll-changing apparatus 26, preferably of the type shown in BuentePatent No. 2,037,210, is therefore disposed besides each stand of thestrip mill in readiness for quickly changing the rolls to form either ahot mill or a cold mill. Furthermore, the run-out delivery tables 4 andI9 .are provided adjacent the strip mill with removable sections, bywhich is meant sections that can be lifted out of place by a crane orotherwise moved out of the way when desired. As shown in Fig. 3, underthe removable run-out table section 27 there is an uncoiler 23, and, asshown in Fig. 4, under the removable delivery table section 3i there isa cold strip reel 32 preferably adapted to exert tension on stripconnected to it.

If it is desired to pickle the coiled strip before placing it in theuncoiler uncovered by table section 21, a coil of the hot rolled stripis taken from storage by a crane, which may be the same one thatdelivers slab piles to the reheating furnace and lifts the removabletable sections, and placed on skids 33 down which it rolls to theloading station of picking apparatus 34 which is desirably of the typedisclosed in Biggert and Buente patentapplication Serial No. 82,542,filed May 29, 1936. The coil is successively immersed in pickling,washing and rinsing tanks after which it runs endwise down an inclinedtable 36 from whence it is transported by the crane or other means touncoiler 28. Strip from this pickled coil is fed through the strip millin which cold rolls have been substituted for the hot rolls, and isconnected to reel 32 from above which table section Si has been removed.As soon as a coil of cold rolled strip is formed on the reel it isremoved therefrom for storage, shipment, or further processing.

W'hiie the cold rolling is being carried on, another supply of ingots isfed over entry table 2 to the universal mill by which they are formedinto slabs that are removed from the side of the run-out table and piledpreparatory to reheating. As soon as all of the pickled coils have beencold rolled the removable table sections are replaced, the cold rollsare removed from the strip mill and the hot rolls replaced therein vbyroll-changing apparatus 2b, and the strip-guiding equipment is changedby suitable apparatus, not shown. The strip mill is then ready toperform hot rolling again, so the slabs that were formed during v theperiod of cold strip rolling are pushed out of the reheating furnace andreduced by the universal mill to bars which are conveyed by the run-outtable to the hot mill in order to repeat the cycle o operation justdescribed.

it will be observed that in practicing the method contemplated by thisinvention hot bars'are produced by the same mill that forms the slabsfrom which they are made, the'bars are ied di- 'rectly from that mill toa hot strip mill that reduces them to strips that are formed into coils,additional ingots are rolled into slabs Aby the first mill after the hotstrip rolling is nished, cold rolls are substituted for the hot rolls ofthe strip mill, the coils of strip may be pickled and the strip is thenrolled in the cold mill just formed while slabs are being produced inthe other mill, and the hot strip rolling equipment is operativelyreassembled in the strip mill after cold rolling therein is nished inorder to reduce to hot strips the bars that are then formed by the rstmill from the slabs previously produced thereby. In short, hot striprolling is carried on in the strip mill while the universal mill isforming slabs into bars, and the universal mill forms ingots into slabswhile cold strip rolling is being carried o n in the strip mill.Consequently, all of the apparatus is kept in operation substantiallilall the time so that there are no prolonged periods during which partsoi it are shut down `which would raise production costs. In addition torequiring a comparatively small investment in apparatus, the layout ofthe apparatus is compact, especially when the furnace, slab transfer,roll-changer and pickler are all disposed on the same side of the xillsas is preferred.;

According to the provisions of the patent statutes, I have explained theprinciple and mode of operation of my invention, and have illustratedanddescribed what I now consider to represent its best embodiment.However, l desire to have it understood that, within the scope of theappended claims, the invention may be practiced otherwise than asspecically illustrated and described.

I claim:

1. The method of rolling metal comprising rolling ingots or the like ina mill to form slabs, reheating the slabs, rolling the slabs in the samemill to form bars, conveying the bars from said mill directly to a hotstrip mill to reduce them to strip, coiling the hot strip, again rollingingots in. said rst mill to form slabs after said hot strip rolling isiinished, exchanging the strip mill equipment necessary for hot rollingfor that needed for cold rolling, cold rolling the hot rolled strip inthe cold strip mill thus formed While slabs are being produced by saidfirst mill, returning said hot rolling equipment to the strip mill aftersaid cold rolling is iinished. and repeating this cycle of rollingwhereby substantially all of the apparatus is maintained insubstantially continuous operation.

2. The method of rolling metal comprising r.,lling ingots in a mill toform slabs, shearing the slabs in a shear, reheating the slabs, rollingthe slabs in the same mill to form bars, shearingthe bars in the sameshear, conveying the bars from said shear directly to a hot strip millto reduce them to strip, coiling the hot strip, again rolling ingots insaid rst mill to form slabs after said hot strip rolling is finished,exchanging the strip mill equipment necessary for hot rolling for thatneeded for cold rolling, cold rolling the hot rolled strip in the coldstrip mill thus formed while slabs are being produced from ingots bysaid rst mill, returning said hot rolling equipment to the strip millafter saidcold rolling is finished, and repeating this cycle of rollingwhereby substantially all of the apparatus is maintained insubstantially continuous operation.

3. Apparatusl for hot and cold rolling metal, comprising a mill forrolling ingots into slabs, means for reheatng said slabs, means forreturning the reheated slabs to said mill for reduction to barstherein,means for delivering said bars from said mill to a hot strip mill forreduction to hot strip therein, means for changing the rolls of saidstrip mill to cold rolls, and means for feeding said hot rolled strip tothe cold strip mill thus formed for cold rolling therein.

Il. Apparatus for hot and cold rolling metal,

.comprising a mill for rolling ingots into slabs,

means for reheating said slabs, means for returning the reheated slabsto said mill for reduction to bars therein, means for delivering saidbars from said mill to a hot strip mill for reduction to hot striptherein, means for'iorming the hot stripl into coils, means for changingthe rolls of said strip mill to cold rolls to form a cold rolling mill,an uncoiler` at one end of the strip mill, and a' reel at the oppositeend of the strip mill, whereby hot rolled strip from said coils disposedin said uncoiler is rolled in said cold rolling mill and wound on saidreel.

5. Apparatus for hot and cold rolling metal, comprising a mill forrolling ingots into slabs, means for reheating said slabs, means forreturning the reheated duction to bars therein, a table for feeding saidbars from said' mill to a hot strip mill, a delivery table for receivinghot strip from said strip mill, each of said tables having a removablesection adjacent the strip mill, an uncoiler mounted below saidremovable feed table section, a cold reel mounted below said removabledelivery table section, a hot coller at the opposite endof said deliverytable, means for changing the rolls of the strip mill to cold rolls toform a cold rolling mill, and means for removing said table sections andfor delivering coils of said hot rolled strip to said uncoiler for coldrolling in said cold rolling mill'.

6. Apparatus for hot and cold rolling metal,

comprising a mill for rolling ingots into slabs, v

a shear for said slabs, means for reheating the sheared slabs, means forreturning the reheated slabs to said mill for reduction to bars therein,

said shear being adapted to shear said bars,

slabs to said mill for recomprising an entry table, means for deliveringversal mill at the delivery end of thetable for hot'rolling equipmenthot rolled strip to'the cold strip mill thus formed means, means forconveying piles of slabs from' for cold rolling therein. the piler to aposition adjacent. said furnace, 15. Apparatus for hot and cold rollingmetal, meansfor` feeding the slabs into the furnace1 comprising an entrytable, means for delivering to reheat them before' returning 'them tosaid ingots thereto, a reheating furnace beside the entry table forreduction to bars in said uni- 5 table, a reversing universal mill atthe delivery versal mill, a strip mill at the delivery end of end of thetable for reducing the ingots to slabs, the run-Out table fOr IOllngSaid bars into hot a run-out table for the slabs, a shear associatedstrip, said strip mill having interchangeable with the run-out table forshearing the slabs, equipment for hetend cold rolling, the deliverytransfer means beside said'run-out table for end of said run-out tablebeing provided with 10 removing sheared slabs therefrom, means for aremovable section, anuncoiler mounted below conveying the removed slabsto said furnace to said table section, a coiler for receiving said hotreheat'them before returning them to said entry Strip from Said stripmill, 'a delivery table extable for reduction to bars in said universalmill, tending from the strip `mill to the coiler and said shear beingadapted to shear the bars, a having a removable section adjacent themill, 15 strip mill at the delivery end of the run-out a cold reelmounted below said delivery table table for rolling said bars into hotstrip, said section, pickling apparatus, and means for constrip millhaving interchangeable hot and coldV veying coils of strip from thecoiler to the pickrolls, the delivery end of said run-out table belingapparatus and for conveying pickled coils ing provided with a removablesection, an unto said uncoiler when said table sections are re- 20coiler mounted below said table section, a coiler moved and cold rollingequipment is substituted for receiving said hot strip from said stripmill, .for the hot rolling equipment of the strip mill a delivery tableextending from the strip mill whereby to cold roll the strip. to thecoiler and having a removable section 17. The method o1A rolling metalcomprising adjacent the mill, a lcold reel mounted below rolling blanksin a mill to form work pieces, con- 25 said delivery table section, andmeans for conveying work pieces while hot from said mill diveying coilsof said hot rolled strip to said unrectly to a hot strip mill to reducethemito strip, coiler whensaid table sections are removed and Vcoilingthe hot strip, continuing the rolling of cold rolls are substituted forthe hot rolls of blanks in said rst mill after said hot strip rollthestrip mill whereby to .cold roll the strip. ing is iinished, exchanging16. Apparatus for hot and cold rolling metal, ment necessary for hotrolling for that needed for cold rolling, cold rolling the hot rolledstrip in the cold strip mill thus formed while blanks ingots thereto, areheating furnace in cooperaare being rolled in said first mill,returning said tive relationship with the table, a reversing uniingotsto slabs, a run-out table cold rolling i! ilnished, and repeating thiscycle for the slabs, a shear associated with the runof rolling wherebysubstantially all of the appaout table, transfer means beside saidrun-out ratllS iS maintained in Substantially 601115111110115 table forremoving sheared slabs therefrom, a operation. slab piler receivingslabs from said transfer reducing the the strip mill equip- 3o to thestrip mill after said u

